Dishwashing appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber for receipt of articles for washing. Various cycles may be included as part of the overall cleaning process. For example, a typical, user-selected cleaning option may include a wash cycle and rinse cycle (referred to collectively as a wet cycle), as well as a drying cycle. In addition, spray-arm assemblies within the wash chamber may be used to apply or direct fluid towards the articles disposed within the rack assemblies in order to clean such articles. As is generally understood, dishwashing appliances may often include multiple spray-arm assemblies, such as a lower spray-arm assembly mounted to the tub at a bottom of the wash chamber, a mid-level spray-arm assembly mounted to one of the rack assemblies, and/or an upper spray-arm assembly mounted to the tub at a top of the wash chamber.
Moreover, dishwashing appliances are typically equipped with a fluid circulation system including a plurality of fluid circulation components for directing fluid to the spray-arm assemblies. Specifically, a pump is typically housed within a machine compartment of the dishwasher that is configured to pump fluid along a circulation flow path for subsequent delivery to the spray-arm assemblies. For example, the fluid discharged from the pump may be routed through a diverter assembly and/or one or more fluid conduits disposed along the circulation flow path prior to being delivered to the spray-arm assemblies.
Fluids used in the cleaning process may be heated. For example, the dishwasher may include one or more heat sources for heating fluids used in wash or rinse cycle and for providing heat during a drying cycle. As another example, the fluid directed through the fluid circulation system may be heated with integrated heating rods or other resistive heating element in the components of the fluid circulation system such as the circulation pump. However, a significant portion of the energy used to heat the fluids may be wasted when the hot fluids are discharged from the dishwasher after being applied to the articles.
Accordingly, an improved heating device for a dishwashing appliance that provides for improved energy usage would be welcomed in the technology.